The purpose of this study is to test the hypothesis that cognitive behavioral therapy (CBT) will improve exercise behavior and physical outcomes. CBT will be used to modify interpretations of exercise. Interpretation is defined as the awareness of sensations, the thoughts and feelings associated with exercise, and the meaning assigned to exercise. General interpretations include abstract information, such as attitudes and beliefs about exercise. Episode-specific interpretations are immediate and occur during and after an episode of exercise. Training older individuals to modify their negative interpretations, both episode-specific and general, to more positive ones through a cognitive behavioral therapy (CBT) intervention may increase exercise behavior/maintenance. Accordingly, the specific aims of this project are to: 1) compare the self-reported exercise behavior 6, 9, and 12 months after initiation of exercise across three groups of older adults: a CBT group, an attention-control group, and a control group; and 2) compare the physical outcomes 6, 9, and 12 months after initiation of exercise across three groups of older adults: a CBT group, an attention-control group, and a control group. Secondary aims are to: 3) compare the health status 6, 9, and 12 months after initiation of exercise across three groups of older adults: a CBT group, an attention-control group, and a control group; and 4) compare episode-specific and general interpretations for individuals who dropout of exercise with individuals who maintain regular exercise. Three hundred forty-three participants will be randomly assigned to a CBT, an attention-control, or a control group. Exercise training will be held constant across all three groups; the experimental group also will receive CBT and the attention-control group will receive health promotion education. Exercise training and the intervention will be completed with 3 months at which time all participants will be encouraged to continue exercising on their own. Exercise behavior, physical outcomes, and health status will be compared at 6, 9, and 12 months after exercise initiation. Health care professionals working with older individuals can use the findings of this study to develop interventions to modify interpretations of exercise thereby enhancing exercise behavior.